ISTANBUL (Reuters) – Turkish Defence Minister Hulusi Akar told U.S. Syria envoy Jim Jeffrey that the United States should give up on building observation posts in Syria, state-owned Anadolu news agency said on Friday.

The United States is setting up “observation posts” along parts of the border between Turkey and Syria to help keep the focus on defeating Islamic State militants in Syria, Defence Secretary Jim Mattis said last month.

Turkey has expressed unease with the plans and has been angry at U.S. support for the YPG, which is a main ally in the fight against Islamic State militants.

Jeffrey is in Turkey for a meeting of the Turkey-U.S. working group on Syria.